C#，FTP上传的代码 FtpWebRequest

private void Upload(string filename)
        {
            string ftpServerIP = "221.12.163.61";
            FileInfo fileInf = new FileInfo(filename);
            string uri = "ftp://221.12.163.61/" + fileInf.Name;
            FtpWebRequest reqFTP;
            // 根据uri创建FtpWebRequest对象
            reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri("ftp://" + ftpServerIP + "/web/" + fileInf.Name));
            // ftp用户名和密码
            reqFTP.Credentials = new NetworkCredential("账户", "密码");
            // 默认为true，连接不会被关闭
            // 在一个命令之后被执行
            reqFTP.KeepAlive = false;
            // 指定执行什么命令
            reqFTP.Method = WebRequestMethods.Ftp.UploadFile;
            // 指定数据传输类型
            reqFTP.UseBinary = true;
            // 上传文件时通知服务器文件的大小
            reqFTP.ContentLength = fileInf.Length;
            // 缓冲大小设置为2kb
            int buffLength = 2048;
            byte[] buff = new byte[buffLength];
            int contentLen;
            // 打开一个文件流 (System.IO.FileStream) 去读上传的文件
            FileStream fs = fileInf.OpenRead();

            try
            {
                // 把上传的文件写入流
                Stream strm = reqFTP.GetRequestStream();
                // 每次读文件流的2kb
                contentLen = fs.Read(buff, 0, buffLength);
                // 流内容没有结束
                while (contentLen != 0)
                {
                    // 把内容从file stream 写入 upload stream
                    strm.Write(buff, 0, contentLen);
                    contentLen = fs.Read(buff, 0, buffLength);
                }
                // 关闭两个流
                strm.Close();
                fs.Close();
                Console.Write("上传成功");
            }
            catch (Exception ex)
            {
               
                Console.Write(ex.Message);
            }
        }